Ask Jack

I'm thinking of upgrading my PC – my current 512MB of memory and 80GB hard disk seem pathetic – but should I wait until Windows 7 in 2010?Peter Atkins

JS: It depends whether you need to upgrade now. If your machine is too slow, you can speed it up significantly by fitting 2GB or even 4GB of memory for less than £50. You can also expand your hard drive space by adding a 500GB or 1TB external hard drive, though you'll only have USB v1 so transferring files will be very slow. This will not be money wasted as you will be able to use the external drive with your next PC as well.

However, you can now get fantastic desktop PCs with DVD or Blu-ray drives, 4GB of memory, dual- or quad-core processors, 64-bit Windows Vista and decent LCD screens for very little money. The extra power may tempt you to do more interesting things, and if your time has any value at all, a new desktop will pay for itself very quickly. And while a clean installation of Windows is always better than an upgrade, the upgrade from Vista SP1 to Windows 7 is as good as this process gets. There is no upgrade from XP to Windows 7: you have to do a clean installation then migrate data.

If you need to upgrade now, I have no hesitation in recommending Vista SP1, if it is correctly installed on good quality hardware. I've read the hate, of course, but I've used Vista myself, and I live with two full-time Vista users who chose it all by themselves, so my experience suggests that most of the hate is ignorant or misguided at best. Yes, it had problems three years ago, but today, I think Vista has fewer problems than XP.

On the other hand, Microsoft will post the first "release candidate" beta version of Windows 7 on 5 May, so everyone will be able to try it. It seems you will not have to wait until 2010 to buy a Windows 7 PC. Depending on how well the testing goes, it could be on sale in three or four months. So, if you definitely need a new PC, your best bet is to wait.

Removing AVG

I downloaded a free version of AVG and it worked really well. After several months, some functions stopped working, so I assumed it was a trial version, not a free version. However, when I tried to remove it, it would not un­install. I tried to remove it manually, but it is still there and blocking all attempts to install another virus checker.Paul Oliver

JS: There is no trial version of AVG: there is a free version (which is free for ever) and a paid-for version with extra features. Loss of functionality may mean another program, or a virus, is blocking it.

Antivirus programs tend to use some deep tricks that make them hard to remove, otherwise viruses could disable them. However, they should uninstall correctly. If not, it's often because the program wasn't installed correctly, or because the installation has been corrupted. The simplest solution is usually to download and install the latest version of the program, then uninstall that.

In AVG's case, the uninstallation option is included as part of the setup wizard. When you try this, disconnect your PC from the net, disable all other security software and reboot your PC before re-installing. Don't run any other programs while you are doing this.

Flat battery

JS: This almost always means the CMOS battery on the motherboard is out of power though, rarely, it could be a memory corruption problem. You will need to take the lid off your PC and look for a flat silver cell of the sort often used in watches and hearing aids. It's very easy to change, but make sure the PC mains power is off and that you are not carrying an electrostatic charge.

Network storage

I'm considering a NAS hard drive for my home network, but I'm unclear about what protects my data. Can I rely on the router firewall and the protected PCs?John Palmer

JS: It's a good question and this is a neglected area. At the moment, I suspect most people rely on the firewall in their router, and use the PC's antivirus software to scan external hard drives. This should be safe enough but doesn't provide real-time protection. Symantec is selling SAV for NAS (Symantec Anti-Virus for Network Attached Storage), but it's not altogether clear how this helps. Storage servers, which run their own operating system, should also be able to run their own antivirus software. A very small example is a Windows Home Server, but this is a much more expensive type of storage.

Backchat

• Paul Foy is interested in ebooks. On the Ask Jack blog, nickpheas recommended manybooks.net, "which acts as a rather more user friendly front end for sites such as Project Gutenberg. It also allows downloading books in about 20 different file formats." Also, Colin Hall has provided a better link for the University of Virginia's ebook library.